Stoneworking is a very old art, dating back to the days of cave dwellers when man is presumed to have first taken shelter within a stone structure. However, the age of the art should not be confused with the level of technology in use today. The desirability of stone in dwellings, for various monuments and markers, and in many other applications continues to be great, owing to intrinsic hardness and resistance to the elements, a wonderful array of diverse natural and enhanced appearances, temperature resistance, thermal mass, low thermal expansion, and other desirable and unusual features. In addition to natural stone, synthetic or artificial stone, stone-containing materials, or stone-like materials are also being manufactured for desired characteristics. Consequently, much modern technology has been applied to further the provision of stone into the marketplace.
Natural stone is quarried in large blocks from mines and is normally next cut into thinner slabs. These slabs are polished on one surface and then typically sold into commercial or construction applications. Exemplary construction applications, though not by any means all-inclusive, are wall surfaces and decorations for both interior and exterior, trim, fireplaces, flooring, table tops, and counter tops. Rarely will the polished slab have the exact dimensions required for a given project. Consequently, the slab must be cut to fit the application. Depending upon the application, once the slab has been cut, the edge may need additional finishing, which may include leveling, shaping and polishing steps. Shaped and polished edges are typically created by grinding the surface with increasingly finer grits of abrasives. The abrasives are normally cooled with a fluid, typically water. As is known in the industry, the cutting, shaping and polishing operations release a large quantity of abrasive, in the form of slurry and dust, which can be quite detrimental to machines and equipment which are not designed to withstand the erosive environment.
Where large quantities of natural stone or stone-like materials are to be cut and polished, relatively massive equipment has been designed and constructed which facilitates the cutting and polishing operations. These machines are generally designed to have enormous mass, which makes the tools much more rigid and also less susceptible to vibration and flexure that may otherwise occur. While these tools are well suited for operations where stones may be readily transported to the machine, they clearly have no utility for stones to be worked in situ at a construction location or the like. Furthermore, these machines tend to be extremely expensive, therefore custom production on this type of machine results in undesirably large amounts of very expensive idle time. Not only do stones need to be changed often for custom production, but the machine will also typically require reconfiguration and/or realignment for the custom job. Furthermore, the transport of a stone to and from a construction site to effect the custom work is not only expensive and the source of much delay, but the likelihood of an accident which destroys the stone is much greater with the additional transport. Finally, these large machines tend to be cost-prohibitive for a smaller shop that is not continuously using the machine. Exemplary patents that illustrate large commercial stone working machines include Adams in U.S. Pat. Nos. 3,164,144; 4,228,617 to Bando; U.S. Pat. No. 5,482,026 to Russell; U.S. Pat. No. 6,006,735 to Schlough et al; U.S. Pat. No. 6,073,621 to Cetrangolo; and U.S. Pat. No. 6,315,799 to Toniolo.
In an attempt to provide a more portable machine which may, for example, be used directly at a job site, other artisans have proposed various rail systems which are clamped or otherwise anchored to stone or other hard material, such as concrete or glass. These rails may act as guides, such as in U.S. Pat. No. 2,014,229 to Emmons; U.S. Pat. No. 4,552,122 to Kelly; U.S. Pat. No. 5,960,780 to Harris; U.S. Pat. No. 6,062,122 to Niemczyk; and U.S. Pat. No. 6,257,225 to Harris; or may alternatively act as a track which supports a trolley or the like. Exemplary trolleys are shown in U.S. Pat. No. 2,291,058 to Pohl; U.S. Pat. No. 3,323,507 to Schuman; U.S. Pat. No. 3,360,298 to Stoljarov et al; U.S. Pat. No. 4,054,179 to Destree; U.S. Pat. No. 4,979,412 to Anders; and U.S. Pat. No. 5,588,418 to Holmes et al. An additional device uses a router with a profiled cutter for shaping and polishing edges. The profiled cutter is an abrasive, and is generally extremely expensive. The nature of these devices only permits the shaped cutter to move into the workpiece along a single axis, causing uneven wear of the cutter. Consequently, a profiled cutter loses its shape with use and creates an edge which varies. This edge will not match the profile of the next cutter of finer grit, and so the next cutter will not make full contact to the edge of the stone. To achieve a polished edge, the mason will need to go back and rework spots or regions missed by mismatched profiles.
For a single cutting operation, many of these devices have found utility in the industry, and rightly so. Providing a guiding edge for an abrasive saw or other cutter, such as is used to cut stone and other hard materials, is of much benefit for custom applications and are frequently required at a building site. When a section of flooring or wall requires custom cutting and fitting, it is not always practical or reasonable to expect a stone factory to size the stone to the needs in advance. Moreover, it may not always be possible to accurately predict the dimensions owing to variability such as spacing between adjacent stone and the like. Furthermore, the thickness of adjacent stones may vary somewhat unpredictably, and the leveling of the intersection of the two stones may be a very important finishing operation.
Unfortunately, many of the prior art devices are designed for only very light duty. Where guides are used, they tend to lack the necessary resistance to abrasion from the stoneworking dust, and consequently have a limited life only suited for very light duty stone working. These machines also illustrate single tool applications. So, when a stone mason identifies the need for a tool to assist with the guiding of a stone cutting saw, he must purchase a guide for his saw. Later, when he elects to purchase a guide for another stone working tool such as a polisher or an edger, he must then purchase another piece of equipment. This single function tool holding and guiding is not highly desirable, and so many masons will perform all but the most complex or sizeable jobs by hand. As is all too well known, when work is completed by hand, there is much greater risk that the mason will err in the process, and this error is not readily remediated in stone. Consequently, the probability for unsightly imperfections or total loss of valuable stone, and the additional work required to remake a destroyed piece or repair an imperfection provides much incentive in the industry for better tools to reduce the dependence upon hand operations. Additionally, the freehand shaping and polishing is very strenuous and time consuming, significantly increasing cost to the consumer.
In addition to the limitations aforementioned, another shortcoming of the prior art apparatus is the ability to guide and form inside openings and corners such as are typically found in the installation of a kitchen or bar sink within a stone counter top. In order to cut this type of hole with inside corners, it is most desirable to drop the saw vertically onto the stone to begin the cut in a predetermined place. Where the design of the cutting guide requires the saw to traverse from an end or edge of the stone, such a guide will have no applicability to the holes created for sinks.
What is desired then is a portable apparatus which enables a stone mason or worker of other hard material to purchase a single apparatus which will perform the precise guiding of diverse tools across the hard material. A need furthermore exists for an apparatus which will allow a mason at a job site to form precise inside holes, shapes and polished surfaces.
The device should be portable and capable of being quickly assembled for use and disassembled for transport. The apparatus should be adapted to move shaped cutting tools into the edge of a workpiece at an acute angle for even tool wear. The apparatus should also be constructed to supply an even pressure to the rotating tool regardless of the depth of cut. The device should also be capable of repeated, accurate traversal along the edge of the workpiece for matching of adjacently positioned pieces.